The present invention relates to a sealed container and a method for assembling it and, more particularly, to a hermetically sealed connection part of a sealed container which is employed as a gas breaker or a gas-insulated switchgear which contains a high-voltage conductor or an electric power device in its inside.
Conventional types of hermetically sealed connection parts of gas-insulated switchgears or the like are disclosed in Japanese Patent Laid-Open Nos. 44313/1981 and 105154/1981. As disclosed, the sealed container of either of the gas-insulated switchgears in which high-voltage conductors are accommodated in an insulated state has the following arrangement: To retain the airtightness of the connection part, single or double grooves are respectively provided in flanges downwardly of bolt holes, and gaskets, such as O-rings, are fitted into the respective grooves to compress and deform the O-rings, whereby the resultant elastic repulsive forces are used to seal the connection part so that the internal pressurized SF.sub.6 gas is prevented from leaking to the outside.
Further, to cope with corrosion of flange faces due to penetration of rainwater or the like, a liquid packing is injected under pressure through an injection opening which communicates with the inside of the flanges, thereby forming an annular gasket between the flanges to retain watertightness.